1) Field of the Invention
This invention relates to a dental X-ray film developing machine for developing one or more exposed dental X-ray films.
2) Description of the Related Art
X-ray pictures of teeth have been used for the diagnosis and treatment of teeth in recent years. X-ray photography of a tooth for obtaining its X-ray picture is effected by bringing an opaque dental X-ray film pack, which contains an X-ray film sealed therein, into a diseased part within a mouth and then exposing the X-ray film to X-rays through the diseased part. By this X-ray photography, a latent image of the tooth is formed on the X-ray film.
After completion of the X-ray photography, the X-ray film pack is taken out of the mouth and is then opened in a dark room or the like to take out the X-ray film. The X-ray film thus taken out is processed for its development, for example, is developed, fixed and washed, whereby an X-ray picture of the thus-taken tooth is obtained on the X-ray film.
A variety of automatic developing machines has heretofore been proposed in order to perform the above development easily without labor, for example, as described in assignee's U.S. Pat. No. 4,853,729 issued Aug. 1, 1989, the subject matter of which is hereby incorporated by reference. The automatic developing machine of the above U.S. Patent will be described with reference to some of the accompanying drawings.
FIG. 1 is a plan view of the dental X-ray film developing machine. FIG. 2 is a cross-sectional view taken along line II--II of FIG. 1. In these drawings, numeral 1 indicates the developing machine. There are shown a circular bottom wall 2a, a cylindrical outer peripheral wall 2a provided upright from the peripheral edge of the bottom wall 2b, and a cylindrical inner peripheral wall 2c provided at a predetermined interval inside the outer peripheral wall 2b. An annular and groove-like space is formed by the bottom wall 2a, outer peripheral wall 2b and inner peripheral wall 2c. Designated at symbols 3a,3b,3c,3d are partition walls provided radially between the outer peripheral wall 2b and inner peripheral wall 2c. The individual partition walls 3a-3d are arranged at predetermined intervals. Owing to the provision of the partition walls 3a-3d, the annular space is divided in four compartments 4a,4b,4c,4d.
Numeral 5 indicates a motor mounted on the bottom wall 2a inside a cylindrical space formed by the bottom wall 2a and inner peripheral wall 2c. The drawings also illustrate a rotary shaft 6 connected to the motor 5 either directly or via a reducing gear unit, not shown, an arm 7 fixed at one end thereof on the rotary shaft 6 and extending radially from the rotary shaft 6, and a suspending portion 7a formed in the opposite, namely, free end of the arm 7. The free end, namely, the suspending portion 7a of the arm 7 is positioned above the annular space and approximately at midpoint between the outer peripheral wall 2b and the inner peripheral wall 2c. Designated at symbols 8a,8b,8c are plugs closing their corresponding discharge openings formed through lower parts of the peripheral outer walls 2b of the respective compartments 4a,4b,4c. Numeral 10 indicates a holder as a film-mounting member, which is adapted to support a dental X-ray film thereon. The structure of the holder 10 will next be described with reference to FIGS. 3(A) and 3(B) which are a plan view of the holder shown in FIG. 2 and a cross-sectional view taken along line III(B)-III(B) of FIG. 3(A), respectively.
The holder 10 is composed of a stem portion 10a, a hole 10b formed through one end portion of the stem portion 10a, and a film-mounting portion 10c formed at the other end portion of the stem portion 10a. The film-mounting portion 10c is bifurcated as is depicted in FIG. 3(A), and slots 10d,10d are formed in inner edges of the bifurcated branches, respectively, as is shown in FIG. 3 (B). By inserting both sides of a dental X-ray film F into the corresponding slots 10d,10d from the free end of the film-mounting portion 10c, the dental X-ray film F is supported on the holder 10.
A description will next be made of development processing making use of the developing machine 1 with reference to an operation schematic illustrated in FIG. 4 in which the individual compartments provided in the toroidal arrangement are shown in a manner developed on a planar sheet. Upon development processing, as is illustrated in FIG. 4, the compartments 4a,4b,4c are filled with a developer S1, a fixer S2 and a washing liquid (not shown) respectively, but the compartment 4d is left as a space. The exposed X-ray film F is taken out of a dental X-ray film pack and is fitted in the slots 10d,10d of the holder 10 so as to support the film F. As is illustrated in FIG. 2, the hole 10b of the holder 10 is fitted on the hook of the suspending portion 7a of the arm 7 so that the holder 10 is suspended from the free end of the arm 7. As will be described subsequently, the arm 7 is set to assume the position shown in FIG. 1, namely, the position close to the partition wall 3a of the compartment 4a. The dental X-ray film F is therefore immersed in the developer S1 when the holder 10 is suspended initially from the suspending portion 7a as described above.
When the motor 5 is driven immediately in the above state, the rotary shaft 6 of the motor 5 rotates so that the free end of the arm 7 starts moving approximately along the angular center line of the compartment 4a. As a result, the dental X-ray film F mounted on the film-mounting portion 10c of the holder 10 is also caused to move through the developer S1. In the course of this movement, the development of the dental X-ray film F is carried out.
When the dental X-ray film F approaches the partition wall 3b, the film-mounting portion 10c of the holder 10 is brought into contact with the tilted surface 2a.sub.1 formed on the bottom wall 2a of the compartment 4a. As the arm 7 moves, the holder 10 is pivoted upwardly about the suspending portion 7a by the tilted surface 2a.sub.1 and eventually rides on the partition wall 3b in a state as indicated by broken lines. When the arm 7 moves further, the film-mounting portion 10c moves on the partition wall 3b and then rides over the partition wall 3b. At this moment, the holder 10 is allowed to pivot downwardly about the suspending portion 7a, whereby the film-mounting portion 10c is dropped in the fixer S2 in the compartment 4b to immerse the dental X-ray film F in the fixer S2. The dental X-ray film F is thereafter caused to move through the fixer S2 to conduct its fixing as the arm 7 moves.
In exactly the same manner, the dental X-ray film F moves into the compartment 4c so that the dental X-ray film F enters a washing liquid. While moving through the washing liquid, its washing is conducted. The dental X-ray film F then moves from the compartment 4c into the compartment 4d. While the dental X-ray film F passes through the compartment 4d, any washing liquid still remaining on the surfaces of the dental X-ray film F are allowed to drop.
After the film F has passed through the compartment 4d, the holder 10 is detached from the arm 7 and the dental X-ray film F is removed from the film-mounting portion 10c of the holder 10. The development processing of the dental X-ray film F has now been completed, so that an X-ray picture of a tooth is shown there.
The above developing machine 1 is suitable for easily developing the exposed dental X-ray film F by a dentist or his assistant in his office. Desirably, the developing machine 1 therefore has small overall dimensions and can be handled easily.
With the construction of the above developing machine 1, replacement of the processing solutions requires advance placement of catch pans below the plugs 8a-8c respectively, and, after pulling out the plugs 8a-8c, it is necessary to wait until the processing solutions are discharged completely. The handling of the developing machine is therefore rather cumbersome.
When development processing is performed using the above developing machine 1, a dentist or the like is required to pick up the holder 10, to fit the hole 10b on the suspending portion 7a of the arm 7 and, after completion of the development, to detach the holder 10 from the arm. The developing machine 1 therefore requires substantial labor in its handling. Further, the developing machine 1 requires stopping of the arm 7 after every full turn to detach the holder 10 with the exposed film F from the arm 7 and then to suspend from the arm 7 another holder with an unexposed film mounted thereon. The developing machine 1 cannot therefore be rotated continuously, leading to the drawback that the work efficiency of development processing is poor.